Acute Hematogenous Osteomyelitis in Children: Clinical Presentation and Management

Clinical characteristics of acute epiphyseal osteomyelitis and acute metaphyseal osteomyelitis of long bones in children

This study aimed to summarize the clinical characteristics of acute epiphyseal osteomyelitis and acute metaphyseal osteomyelitis of long bones in children. Data of 43 children with acute osteomyelitis of long bones diagnosed and treated from November 2017 to January 2021 were retrospectively analyzed. Medical records, laboratory results, and MRI were reviewed. Surgical drainage of lesions was done to retrieve infective fluid and tissue for examination. There were 12 cases of metaphyseal and epiphysis involvement, including five boys and seven girls, aged from 1 to 12 years old, and the length of hospitalization was 21-45 days. There were six cases of distal femur, five cases of proximal tibia, and one case of distal humerus. The pathogenic microorganisms were methicillin-sensitive Staphylococcus aureus (MSSA) in six cases and methicillin-resistant Staphylococcus aureus (MRSA) in six cases. No complications were reported during the follow-up. Thirty-one cases of simple metaphyseal involvement, including 20 boys and 11 girls, aged 19 days to 12 years, and the length of hospitalization was 18-60 days. Twelve cases of distal femur, 11 cases of proximal tibia, three cases of distal humerus, two cases of proximal tibiofibular, two cases of proximal fibula, and one case of proximal ulna. The pathogenic microorganism was MSSA in 26 cases and MRSA in five cases. One patient with knee contracture during follow-up. Epiphyseal osteomyelitis is rare but can occur in older children. The prognosis is good with aggressive surgical treatment.

Comprehensive Analysis of the Spectrum of Osteoarticular Infections in Children

BACKGROUND

Studies of pediatric osteoarticular infections (OAIs) mostly focus on acute hematogenous osteomyelitis (AHO) and acute bacterial arthritis (ABA). A comprehensive descriptive analysis of pediatric OAIs, including subacute, chronic, and non-hematogenous types, is lacking.

METHODS

A detailed analysis of all pediatric OAIs was undertaken at 2 academic centers, Hasbro Children's Hospital, Providence, RI, and Nationwide Children's Hospital, Columbus, OH. Infections were classified as AHO (with or without suppurative arthritis), isolated ABA, subacute or chronic hematogenous osteomyelitis (SCHO), non-hematogenous osteoarticular infection (NHI), or hardware-associated osteoarticular infection (HOI). Clinical, radiological, and laboratory characteristics were compared.

RESULTS

A total of 582 consecutive cases of OAIs were included: 295 AHO (51%), 88 ABA (15%), 76 NHI (13%), 73 HOI (13%), and 50 SCHO (9%). Median age was significantly higher for HOI (14.5 years), NHI (11.8), and SCHO (10.4) than for AHO (9) and ABA (5) (P < .001). Patients with AHO or ABA were more likely (P < .001) to be febrile (each 84%) compared with other groups (45%-56%) and had higher biomarkers of inflammation (white blood cell, erythrocyte sedimentation rate, C-reactive protein). A causative organism was identified in 74% of cases, mostly from tissue specimens (78%). Staphylococcus aureus was the most common organism across infection types (34%-55% of cases), while polymicrobial infection was common in NHI (22%) and HOI (21%). Chronic morbidity complicated infections in 89 (15%) patients, the majority of whom (66%) had SCHO, NHI, or HOI.

CONCLUSIONS

SCHO, NHI, and HOI accounted for a significant proportion of pediatric OAIs and contributed disproportionately to chronic morbidity.

Early Bone Ischemia in Pediatric Acute Hematogenous Osteomyelitis and its Association With Progression to Chronic Osteomyelitis: New Insights From Gadolinium-enhanced Subtraction MRI

BACKGROUND

Acute hematogenous osteomyelitis (AHO), the most common osteoarticular infection in children, carries a significant risk for chronic complications. Predicting chronic complications early in the course of disease is challenging. The underlying pathogenesis of complications is not fully understood.

METHODS

Children who presented to Sultan Qaboos University Hospital, Muscat, Oman between January 2015 and April 2022 for AHO were identified by a search of magnetic resonance imaging (MRI) records. Children between 1 month and 18 years of age who did not meet exclusion criteria, and whose MRI also included gadolinium-enhanced subtraction (GES) sequences were included in the analysis. Outcomes were compared between patients who showed early evidence of bone ischemia and those who did not.

RESULTS

The analysis included 11 children who had GES MRI sequences from among 18 AHO cases in total. Median age was 5 years (IQR, 4-9), and 82% were males. Median duration of symptoms at presentation was 5 days (IQR, 3-7). GES sequences showed early bone ischemia in 6 of 11 (55%) patients. Patients with early bone ischemia were treated with significantly longer durations of IV antibiotics (median 23 vs. 10 days, P = 0.017) and oral antibiotics (median 134 vs. 29 days, P = 0.004), and required more surgical debridements (median 3 vs. 0 debridements, P = 0.017). Chronic osteomyelitis only developed among patients with early bone ischemia (5/6 vs. 0/5, P = 0.015).

CONCLUSIONS

In pediatric AHO, GES MRI sequences revealed early bone ischemia in a significant proportion of patients. Early bone ischemia was strongly associated with progression to chronic osteomyelitis.

Infection prevention-how can we prevent transmission of community-onset methicillin-resistant Staphylococcus aureus?

BACKGROUND

Staphylococcus aureus is a versatile organism, capable of existing as a commensal organism while also possessing pathogenic potential. The emergence of clinically and genetically distinct strains of methicillin-resistant S. aureus (MRSA), termed community-onset MRSA (CO-MRSA), resulted in an epidemic of invasive and skin and soft tissue infections (SSTI) in otherwise healthy individuals without traditional risk factors. Colonization with S. aureus is a risk factor for developing infection and also a source of transmission to close contacts. Outbreaks of S. aureus SSTI have been described in crowded settings and within households. Thus, preventive strategies are essential to interrupt recurrent infections.

OBJECTIVES

The objective of this narrative review is to provide a comprehensive, evidence-based approach to prevent transmission of CO-MRSA. We highlight key clinical trials that emphasize the importance of household and environmental S. aureus colonization in propagating household transmission. Finally, we highlight research priorities to prevent S. aureus infection.

SOURCES

We cite primary literature from peer-reviewed publications as sources for this review.

CONTENT

Our recommended approach to the management of individuals presenting with skin abscesses includes optimal treatment of the initial infection and hygiene education. Decolonization measures should be recommended for individuals with recurrent SSTIs or whose household members have SSTIs. Targeted decolonization with topical antimicrobials should be prescribed to all affected individuals within the household.

IMPLICATIONS

S. aureus infections result in substantial mortality and morbidity because of the high incidence of recurrent skin infections. Although current decolonization strategies are beneficial, interventions are often costly to families and effectiveness wanes over time. Results from a recently completed trial evaluating integrated periodic decolonization and household environmental hygiene will further add to our understanding of what constitutes a sustainable decolonization approach. In addition, novel preventive strategies are being developed such as S. aureus vaccines, lytic agents, probiotics, microbiota transplants, and phage therapy.

Accuracy of pathogen diagnostic codes for acute hematogenous musculoskeletal infections in children

Administrative databases are powerful tools for pediatric research but lack patient-level microbiology results. This study aimed to determine the accuracy of pathogen discharge diagnosis codes for children hospitalized with acute hematogenous musculoskeletal infections (MSKIs). Medical records for 244 children hospitalized with acute hematogenous MSKIs were manually reviewed to determine which bacterial pathogen, if any, was identified for each MSKI based on microbiology results obtained during the hospitalization. Microbiology results for each patient were then compared to their discharge diagnoses in the Pediatric Health Information System (PHIS) database to determine the accuracy of pathogen discharge codes. Discharge diagnostic codes correctly matched the microbiology results in 89.3% of encounters. Sensitivity and specificity for Staphylococcus aureus discharge diagnostic codes were 88.6% and 96.4% respectively for methicillin-susceptible S. aureus and 92.9% and 99.5% for methicillin-resistant S. aureus. Pathogen discharge codes are reliable surrogates that accurately reflect the microbiology results for children with MSKIs.

Clinical characteristics and prognosis of children with culture-negative osteoarticular infections: a meta-analysis based on cohort studies

Purpose

Pediatric osteoarticular infections (OAIs) are an orthopedic emergency that can lead to severe sequelae if not treated appropriately. Approximately half of the patients with OAIs in clinical practice fail to obtain microbiological results even after undergoing aspiration or surgery, which presents a significant challenge in clinical practice. The inability to identify pathogens can lead to incorrect antibiotic usage or under-treatment, increasing the risk of adverse outcomes. This study aims to investigate the clinical characteristics and prognosis of culture-negative OAIs compared to culture-positive OAIs through a meta-analysis, providing insights to optimize treatment strategies.

Methods

A systematic search was conducted to identify cohort studies comparing the clinical characteristics and prognosis of children with culture-negative OAIs to those with culture-positive OAIs. The search encompassed the databases of Wanfang Data, China National Knowledge Infrastructure, China Biology Medicine disc, Excerpta Medica Database, PubMed and the Cochrane Library, with the literature review extending up to March 2024. Data were extracted from eligible articles and assessed using the Newcastle-Ottawa scale, and the articles were selected based on predefined inclusion and exclusion criteria.

Results

Twelve literature reports covering 1630 patients were included in this meta-analysis. Publication bias did not significantly affect the results. The incidence of long-term sequelae, temperature before admission, baseline laboratory indicators and possibility of surgery in the culture-negative group of patients were significantly lower than those in the culture-positive group. In addition, there were no significant differences in gender, age, race, trauma history, patient delay, antibiotic usage before admission or clinical symptoms between the two groups.

Conclusions

Children diagnosed with culture-negative OAIs generally demonstrated less severe systemic inflammatory responses, required shorter treatment durations, exhibited a reduced likelihood of requiring surgical intervention and were less prone to experience long-term functional impairments compared to children with culture-positive OAIs. However, no differences in patient characteristics and clinical symptoms were found between the two groups. Further large-scale studies are still required to validate these findings.

Type of study

Meta-analysis.

Level of evidence

Level III.

A transformer-based deep learning model for identifying the occurrence of acute hematogenous osteomyelitis and predicting blood culture results

Background

Acute hematogenous osteomyelitis is the most common form of osteomyelitis in children. In recent years, the incidence of osteomyelitis has been steadily increasing. For pediatric patients, clearly describing their symptoms can be quite challenging, which often necessitates the use of complex diagnostic methods, such as radiology. For those who have been diagnosed, the ability to culture the pathogenic bacteria significantly affects their treatment plan.

Method

A total of 634 patients under the age of 18 were included, and the correlation between laboratory indicators and osteomyelitis, as well as several diagnoses often confused with osteomyelitis, was analyzed. Based on this, a Transformer-based deep learning model was developed to identify osteomyelitis patients. Subsequently, the correlation between laboratory indicators and the length of hospital stay for osteomyelitis patients was examined. Finally, the correlation between the successful cultivation of pathogenic bacteria and laboratory indicators in osteomyelitis patients was analyzed, and a deep learning model was established for prediction.

Result

The laboratory indicators of patients are correlated with the presence of acute hematogenous osteomyelitis, and the deep learning model developed based on this correlation can effectively identify patients with acute hematogenous osteomyelitis. The laboratory indicators of patients with acute hematogenous osteomyelitis can partially reflect their length of hospital stay. Although most laboratory indicators lack a direct correlation with the ability to culture pathogenic bacteria in patients with acute hematogenous osteomyelitis, our model can still predict whether the bacteria can be successfully cultured.

Conclusion

Laboratory indicators, as easily accessible medical information, can identify osteomyelitis in pediatric patients. They can also predict whether pathogenic bacteria can be successfully cultured, regardless of whether the patient has received antibiotics beforehand. This not only simplifies the diagnostic process for pediatricians but also provides a basis for deciding whether to use empirical antibiotic therapy or discontinue treatment for blood cultures.

Haematogenous polyostotic osteomyelitis caused by Serratia marcescens in a cat

A 2-year-old female Bengal cat was referred for acute right forelimb lameness one month after ovariectomy. Physical examination revealed multifocal pain on bone palpation and fever. Radiographs showed mixed lytic-proliferative polyostotic diaphyseal osteopathy of multiple bone segments. Histopathologic evaluation of bone biopsies showed severe chronic pyogranulomatous osteomyelitis and multidrug-resistant Serratia marcescens was cultured. Antibiotic therapy with piperacillin-tazobactam was administered for 60 days, based on susceptibility testing. Lameness and bone pain resolved within 15 days, and radiographs after 30 days showed decreased bone lysis. At a 6-month recheck, the cat recovered completely, and only bone remodelling was evident on radiographs. Multifocal bacterial haematogenous osteomyelitis (HO) caused by Serratia marcescens was diagnosed in an adult immunocompetent cat. HO is infrequently reported in dogs and cats with young and immunocompromised patients being most at risk. Prior ovariectomy and anaesthesia may have predisposed the cat to the development of a hospital-associated infection (HAI), as other aetiologies or predisposing causes for osteomyelitis were reasonably excluded. Serratia marcescens is a gram-negative bacterium recently reported as responsible for human and veterinary HAIs, although it has never been stated for HO in small animals. Early recognition and antibiotic therapy led to good outcome in this case.

A case of early-onset congenital syphilitic osteomyelitis of the calcaneus and literature review

BACKGROUND

Congenital syphilis (CS) is a sexually transmitted disease caused by Treponema pallidum (TP). When the skeletal system is involved, it often results in multiple, symmetrical bone destruction at the epiphyses of long tubular bones such as the humerus and radius, rarely involving the calcaneus. This article reports a case of calcaneal osteomyelitis caused by TP in a child with no other bone damage and subtle clinical manifestations, No similar cases have been reported.

CASE PRESENTATION

A 4-month-old male infant presented with right foot swelling without any obvious cause and no history of trauma. X-ray and CT scans showed bone loss in the calcaneus and surrounding soft tissue swelling. Review of past medical records revealed that the infant had been diagnosed with CS infection during a hospital stay for "pneumonia" at one month old. The parents refused surgery, opting for conservative treatment at an external hospital for three weeks, during which the symptoms of the affected foot showed no significant improvement. Subsequently, the child was treated at our hospital with surgery, including lesion removal and cast fixation, followed by oral antibiotic treatment. The last follow-up showed no swelling or tenderness in the affected foot, with good mobility, and X-rays indicated that the bone had essentially returned to normal.

CONCLUSIONS

Early CS rarely involves the calcaneus. When diagnosing unexplained calcaneal osteomyelitis in infants, this rare cause should be considered. A thorough medical history should be taken and a careful physical examination conducted. Once diagnosed, timely surgical debridement and appropriate antibiotic therapy targeting TP infection are required. Early identification and intervention can result in a good prognosis without related complications.

Predictive value of PAR and PNI for the acute complicated course of pediatric acute hematogenous osteomyelitis

OBJECTIVE

Platelet to albumin ratio (PAR) and prognostic nutritional index (PNI) are potential indicators for evaluating nutritional and inflammatory status. This study aimed to examine the relationship between PAR and PNI and the acute complicated course of acute hematogenous osteomyelitis (AHO).

METHODS

AHO patients were divided into the simple course group and the acute complicated course group. The patient's gender, age, site of infection, body temperature, laboratory results, and pathogen culture results were collected and compared. Multivariate logistic regression analysis was used to determine the independent risk factors of the acute complicated course group. The receiver operating characteristic curve was applied to determine the optimal cut-off value.

RESULTS

In total, 101 AHO patients with a median age of 7.58 years were included. There were 63 cases (62.4 %) in the simple course group and 38 cases (37.6 %) in the complicated course group. Binary logistic regression analysis revealed that PAR and PNI were independent risk factors for predicting the acute complicated course of AHO (p = 0.004 and p < 0.001, respectively). Receiver operating characteristic curve analysis demonstrated that the combination of PAR and PNI had an area under the curve of 0.777 (95 % CI: 0.680-0.873, p < 0.001) with a cut-off value of 0.51.

CONCLUSIONS

The incidence of acute complicated courses was significantly higher in patients with high PAR and low PNI. A combined factor greater than 0.51, derived from PAR and PNI measurements within 24 h of admission, may be useful for predicting AHO patients who are likely to develop severe disease.

Analysis of poor prognostic factors for septic arthritis of the hip in children: a case series of 76 patients

The clinical characteristics, treatment and outcomes of children with septic arthritis of the hip in our hospital were analyzed to identify the risk factors for a poor prognosis. The clinical data of 76 children with septic arthritis of the hip who were treated at our hospital from January 2010 to December 2020 were retrospectively analyzed. According to the most recent follow-up data, the patients were classified as good prognosis or poor prognosis. The differences between the two groups were analyzed. From January 2010 to December 2020, a total of 76 children with septic arthritis of the hip were admitted to our hospital, comprising 52 (68.4%) with a good prognosis and 24 (31.6%) with a poor prognosis. The risk of a poor prognosis was significantly higher in the group with time from onset to surgery >22 days than in the group with time from onset to surgery <11 days. The risk of poor prognosis in the group with C-reactive protein (CRP) > 100 mg/L was significantly higher than that in the group with CRP < 20 mg/L. Time from onset to surgery >14 days and CRP > 93 mg/L were the cutoff values for a poor prognosis. Significant elevation of CRP and prolonged time from onset to surgery in children with septic arthritis of the hip are risk factors for a poor prognosis. Early diagnosis and effective treatment are very important because delays in these factors can lead to a poor prognosis. Level of Evidence: Level II, retrospective study.

Pseudoparalysis in an infant with otitis media: an evolving presentation of scapular osteomyelitis

A female infant presented to an Irish hospital with a 4-day history of fever, irritability and reduced oral intake. Initial inflammatory markers were significantly elevated, an erythematous tympanic membrane was noted on examination and an initial diagnosis of acute otitis media was made. By the third hospital day, the infant was noted to be irritable when being lifted up; pseudoparalysis of the right upper limb was observed. A radiograph of the right shoulder was normal; MRI identified acute scapular osteomyelitis with subperiosteal abscess formation. The child underwent 3 washout procedures and received 6 weeks of antibiotic therapy, with full clinical recovery at 3 months. This case highlights the importance of remaining flexible in the context of an evolving presentation and recognising hallmarks of musculoskeletal infection, fever, localised pain and pseudoparalysis. Additionally, we review the literature to highlight clues in diagnosis, treatment and outcome for paediatric acute scapular osteomyelitis.

First-Generation Cephalosporins for Treatment of Acute Hematogenous Osteomyelitis in Children: A Study of Efficacy and Adverse Effects

Background

Acute hematogenous osteomyelitis (AHO) is a relatively infrequent but significant infection in pediatric patients. As Staphylococcus aureus is the most common cause of AHO, intravenous and oral first-generation cephalosporins are common therapies. Cephalexin is a commonly prescribed oral therapy for pediatric AHO, although it requires frequent dosing that may affect adherence. Cefadroxil is a comparable oral first-generation cephalosporin with a more desirable dosing schedule.

Methods

We reviewed pediatric patients admitted to Mayo Clinic between March 2002 and September 2020 for management of AHO who received treatment with a first-generation cephalosporin. We reviewed timing of oral therapy transition, therapy-associated adverse effects, and recurrence of disease after completion of therapy.

Results

There were 59 patients included in the study. There was similar occurrence of adverse effects in patients receiving cefadroxil and cephalexin, although use of cefadroxil coincided with more gastrointestinal adverse effects and leukopenia and use of cephalexin with more rash and neutropenia. One secondary treatment failure occurred in our study, in a patient receiving cephalexin for treatment of septic arthritis.

Conclusions

Cefadroxil may be a reasonable alternative oral therapy for methicillin-susceptible S aureus or culture-negative AHO in pediatric patients, particularly when a less frequent dosing schedule is desired. Future study with a larger sample size is warranted.

Treatment of bone infections in children in low-income countries - A practical guideline based on clinical cases

In low-income countries (LIC), the management of bone infections is a huge challenge. A high number of patients are in the pediatric age group. Children and adolescents exhibit good bone healing potential offering treatment options that mainly rely on the biological response of the infected bone. The purpose of this article is to highlight treatment options for these patients in LIC, which is based on clinical cases that illustrate the principles of the treatment, focusing on bone reaction and healing potential. First, identification of emergency cases is of importance. Sepsis of the patient due to bone infections is a life-threatening disease that requires immediate surgical attention with abscess incision. It should be tailored to the surgeon's experience and local conditions to avoid unwanted complications, such as excessive bleeding, fracture or bone loss. In non-septic patients, uncomplicated cases should be distinguished from complicated cases as the first might often require only abscess incision, particularly in small children, without any other major surgical intervention. Biomechanical stability and bone formation capacity, soft tissue conditions and joint involvement are decisive factors differentiating uncomplicated from complicated cases. Central treatment column is the immobilization of the infected bone with simple methods, such as plaster of Paris, braces or external fixation. This is intended to provide sufficient stability to allow for new bone formation that subsequently downsizes the infection site and that can bridge previously infected non-union sites or bone defects. In most cases, antibiotic treatment is not performed as antibiotics are not available or affordable. Severe soft tissue defects remain a major challenge as microvascular surgical experience is often required for reliable coverage, for which referral to one of the very few specialized centers is recommended. Major bone defects should also be treated in centers with sufficient expertise for bone reconstruction procedures. Regular follow-ups are important to ensure healing and to avoid aggravation of the disease. Encouraging success rates can be achieved by these treatment principles. However, it should not be forgotten that poverty in these countries, including limited access to health care, remains one of the world's most important problems.

Vitamin D deficiency triggers intrinsic apoptosis by impairing SPP1-dependent antiapoptotic signaling in chronic hematogenous osteomyelitis

Chronic hematogenous osteomyelitis (CHOM) is a common bone disease characterized by the development of sequestra after bacterial infection. Emerging evidence has shown that vitamin D (VD) deficiency raises the risk of osteomyelitis, but the underlying mechanisms remain obscure. Here, we establish a CHOM model in VD diet-deficient mice by intravenous inoculation of Staphylococcus aureus. Whole-genome microarray analyses using osteoblast cells isolated from sequestra reveal significant downregulation of SPP1 (secreted phosphoprotein 1). Molecular basis investigations show that VD sufficiency activates the VDR/RXR (VD receptor/retinoid X receptor) heterodimer to recruit NCOA1 (nuclear receptor coactivator 1) and transactivate SPP1 in healthy osteoblast cells. Secreted SPP1 binds to the cell surface molecule CD40 to activate serine/threonine-protein kinase Akt1, which then phosphorylates forkhead box O3a (FOXO3a), blocking FOXO3a-mediated transcription. By contrast, VD deficiency impairs the NCOA1-VDR/RXR-mediated overexpression of SPP1, leading to the inactivation of Akt1 and the accumulation of FOXO3a. FOXO3a then upregulates the expression of the apoptotic genes BAX (Bcl2-associated X-protein), BID (BH3 interacting death domain), and BIM (Bcl2-interacting mediator of cell death), to induce apoptosis. Administration of the NCOA1 inhibitor gossypol to the CHOM mice also promotes the occurrence of sequestra. VD supplementation can reactivate the SPP1-dependent antiapoptotic signaling and improve the outcomes of CHOM. Collectively, our data reveal that VD deficiency promotes bone destruction in CHOM by the removal of SPP1-dependent antiapoptotic signaling.

Murine models of orthopedic infection featuring Staphylococcus aureus biofilm

Introduction: Osteomyelitis remains a major clinical challenge. Many published rodent fracture infection models are costly compared with murine models for rapid screening and proof-of-concept studies. We aimed to develop a dependable and cost-effective murine bone infection model that mimics bacterial bone infections associated with biofilm and metal implants. Methods: Tibial drilled hole (TDH) and needle insertion surgery (NIS) infection models were compared in C57BL/6 mice (female, N = 150 ). Metal pins were inserted selectively into the medullary canal adjacent to the defect sites on the metaphysis. Free Staphylococcus aureus (ATCC 12600) or biofilm suspension (ATCC 25923) was locally inoculated. Animals were monitored for physiological or radiographic evidence of infection without prophylactic antibiotics for up to 14 d. At the end point, bone swabs, soft-tissue biopsies, and metal pins were taken for cultures. X-ray and micro-CT scans were performed along with histology analysis. Results: TDH and NIS both achieved a 100 % infection rate in tibiae when a metal implant was present with injection of free bacteria. In the absence of an implant, inoculation with a bacterial biofilm still induced a 40 %-50 % infection rate. In contrast, freely suspended bacteria and no implant consistently showed lower or negligible infection rates. Micro-CT analysis confirmed that biofilm infection caused local bone loss even without a metal implant as a nidus. Although a metal surface permissive for biofilm formation is impermeable to create progressive bone infections in animal models, the metal implant can be dismissed if a bacterial biofilm is used. Conclusion: These models have a high potential utility for modeling surgery-related osteomyelitis, with NIS being simpler to perform than TDH.

Efficacy and safety of vancomycin-loaded calcium sulfate versus conventional surgical debridement for pediatric acute osteomyelitis: a retrospective study

BACKGROUND

The purpose of this study was to evaluate the safety and efficacy of vancomycin-loaded calcium sulfate beads and negative-pressure wound therapy (NPWT) in treating children with acute hematogenous osteomyelitis (AHOM).

METHODS

A retrospective cohort study was conducted from January 2017 to January 2020 examining children (n = 60) with AHOM who were treated with surgical debridement followed by vancomycin-loaded calcium sulfate beads and NPWT (n = 32) and compared to treatment by conventional surgical debridement (n = 28) followed by NPWT. Conventional surgical treatment consisted of fenestration of necrotic infected bone, debridement of surrounding soft tissue, and washing of the medullary canal before the application of NPWT. In the vancomycin group, the antibiotic-loaded beads were implanted after washing the medullary canal and before the application of NPWT. Epidemiological factors, complications during the procedure, outcomes at last follow-up (30.0 ± 11.7 months, range 13-58 months), and laboratory parameters were documented and compared between the two groups.

RESULTS

Good outcomes were achieved at last follow-up in 71.4% of the conventional treatment group and 75% of the vancomycin group. In the vancomycin group, it took a mean of 4.8 ± 2.5 days for CRP levels to decrease to 50% of initial inflammatory levels compared to 13 ± 9.6 days for the conventional treatment group (p = 0.001, t-test). The conventional group also had seven patients who underwent four or more surgeries whereas no patients in the vancomycin group underwent more than three surgeries (p = 0.013, chi-square test).

CONCLUSION

Localized vancomycin delivery with NPWT effective for treating cases of AHOM that required. No perioperative adverse reactions or complications occurred from this treatment method. Based on the shortened recovery period of CRP levels, prolonged administration of post-operational parenteral antibiotics can possibly be reduced with this treatment method.

Microbiological aspects of osteomyelitis in veterinary medicine: drawing parallels to the infection in human medicine

Osteomyelitis is a challenging infectious disease affecting humans and animals. It is difficult to diagnose because, in many cases, symptoms are non-specific and, for example in implant-related cases, can appear long time after surgery. In addition to this, it is also difficult to treat due to the need to find the appropriate antibiotic regime and delivery system to reach the site of infection and to avoid development of bacterial resistance. The central purpose of this review is to compare the microbiological aspects of osteomyelitis in human and veterinary medicine, with the aim of improving the microbiological diagnosis and treatment of this infection in animals. Furthermore, the study of osteomyelitis in animals may help to improve the development of animal models for testing new treatments in humans. Host factors and underlying conditions have been studied mainly in humans, although aspects as immunodeficiency have been described in some veterinary cases. Even when Staphylococcus aureus is still considered the most prevalent causing microorganism, this prevalence should be reviewed using molecular diagnostic techniques, and this could affect treatment options. New approaches to treatment include local delivery of antibiotics using different biomaterials, antimicrobial photodynamic therapy, and new antimicrobial compounds. We would like to remark the need of large, high-quality clinical trials and of the development of guides for the diagnosis and treatment of osteomyelitis in different animal species.

New insights in pediatrics in 2021: choices in allergy and immunology, critical care, endocrinology, gastroenterology, genetics, haematology, infectious diseases, neonatology, neurology, nutrition, palliative care, respiratory tract illnesses and telemedicine

In this review, we report the developments across pediatric subspecialties that have been published in the Italian Journal of Pediatrics in 2021. We highlight advances in allergy and immunology, critical care, endocrinology, gastroenterology, genetics, hematology, infectious diseases, neonatology, neurology, nutrition, palliative care, respiratory tract illnesses and telemedicine.

The osteoblast secretome in Staphylococcus aureus osteomyelitis

Osteomyelitis (OM) is an infectious disease of the bone predominantly caused by the opportunistic bacterium Staphylococcus aureus (S. aureus). Typically established upon hematogenous spread of the pathogen to the musculoskeletal system or contamination of the bone after fracture or surgery, osteomyelitis has a complex pathogenesis with a critical involvement of both osteal and immune components. Colonization of the bone by S. aureus is traditionally proposed to induce functional inhibition and/or apoptosis of osteoblasts, alteration of the RANKL/OPG ratio in the bone microenvironment and activation of osteoclasts; all together, these events locally subvert tissue homeostasis causing pathological bone loss. However, this paradigm has been challenged in recent years, in fact osteoblasts are emerging as active players in the induction and orientation of the immune reaction that mounts in the bone during an infection. The interaction with immune cells has been mostly ascribed to osteoblast-derived soluble mediators that add on and synergize with those contributed by professional immune cells. In this respect, several preclinical and clinical observations indicate that osteomyelitis is accompanied by alterations in the local and (sometimes) systemic levels of both pro-inflammatory (e.g., IL-6, IL-1α, TNF-α, IL-1β) and anti-inflammatory (e.g., TGF-β1) cytokines. Here we revisit the role of osteoblasts in bacterial OM, with a focus on their secretome and its crosstalk with cellular and molecular components of the bone microenvironment and immune system.

Mini Review Therapeutic Strategies Targeting for Biofilm and Bone Infections

Bone infection results in a complex inflammatory response and bone destruction. A broad spectrum of bacterial species has been involved for jaw osteomyelitis, hematogenous osteomyelitis, vertebral osteomyelitis or diabetes mellitus, such as Staphylococcus aureus (S. aureus), coagulase-negative Staphylococcus species, and aerobic gram-negative bacilli. S. aureus is the major pathogenic bacterium for osteomyelitis, which results in a complex inflammatory response and bone destruction. Although various antibiotics have been applied for bone infection, the emergence of drug resistance and biofilm formation significantly decrease the effectiveness of those agents. In combination with gram-positive aerobes, gram-negative aerobes and anaerobes functionally equivalent pathogroups interact synergistically, developing as pathogenic biofilms and causing recurrent infections. The adhesion of biofilms to bone promotes bone destruction and protects bacteria from antimicrobial agent stress and host immune system infiltration. Moreover, bone is characterized by low permeability and reduced blood flow, further hindering the therapeutic effect for bone infections. To minimize systemic toxicity and enhance antibacterial effectiveness, therapeutic strategies targeting on biofilm and bone infection can serve as a promising modality. Herein, we focus on biofilm and bone infection eradication with targeting therapeutic strategies. We summarize recent targeting moieties on biofilm and bone infection with peptide-, nucleic acid-, bacteriophage-, CaP- and turnover homeostasis-based strategies. The antibacterial and antibiofilm mechanisms of those therapeutic strategies include increasing antibacterial agents’ accumulation by bone specific affinity, specific recognition of phage-bacteria, inhibition biofilm formation in transcription level. As chronic inflammation induced by infection can trigger osteoclast activation and inhibit osteoblast functioning, we additionally expand the potential applications of turnover homeostasis-based therapeutic strategies on biofilm or infection related immunity homeostasis for host-bacteria. Based on this review, we expect to provide useful insights of targeting therapeutic efficacy for biofilm and bone infection eradication.

The Underlying Molecular Basis and Mechanisms of Venous Thrombosis in Patients with Osteomyelitis: A Data-Driven Analysis

Objective

Osteomyelitis (OM) is one of the most risky and challenging diseases. Emerging evidence indicates OM is a risk factor for increasing incidence of venous thromboembolism (VTE) development. However, the mechanisms have not been intensively investigated.

Methods

The OM-related dataset GSE30119 and VTE-related datasets GSE19151 and GSE48000 were downloaded from the Gene Expression Omnibus (GEO) database and analyzed to identify the differentially expressed genes (DEGs) (OMGs1 and VTEGs1, respectively). Functional enrichment analyses of Gene Ontology (GO) terms were performed. VTEGs2 and OMGs2 sharing the common GO biological process (GO-BP) ontology between OMGs1 and VTEGs1 were detected. The TRRUST database was used to identify the upstream transcription factors (TFs) that regulate VTEGs2 and OMGs2. The protein-protein interaction (PPI) network between VTEGs2 and OMGs2 was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and then visualized in Cytoscape. Topological properties of the PPI network were calculated by NetworkAnalyzer. The Molecular Complex Detection (MCODE) plugin was utilized to perform module analysis and choose the hub modules of the PPI network.

Results

A total of 587 OMGs1 and 382 VTEGs1 were identified from the related dataset, respectively. GO-BP terms of OMGs1 and shared DGEs1 were mainly enriched in the neutrophil-related immune response process, and the shared GO-BP terms of OMGs1 and VTEGs1 seemed to be focused on cell activation, immune, defense, and inflammatory response to stress or biotic stimulus. 230 VTEGs2, 333 OMGs2, and 13 shared DEGs2 were detected. 3 TF-target gene pairs (SP1-LSP1, SPI1-FCGR1A, and STAT1-FCGR1A) were identified. The PPI network contained 1611 interactions among 467 nodes. The top 10 hub proteins were TP53, IL4, MPO, ELANE, FOS, CD86, HP, SOCS3, ICAM1, and SNRPG. Several core nodes (such as MPO, ELANE, and CAMP) were essential components of the neutrophil extracellular traps (NETs) network.

Conclusion

This is the first data-mining study to explore shared signatures between OM and VTE by the integrated bioinformatic approach, which can help uncover potential biomarkers and therapeutic targets of OM-related VTE.

Whole genome sequencing and molecular epidemiology of pediatric Staphylococcus aureus bacteremia

BACKGROUND

The role Staphylococcus aureus antimicrobial resistance genes and toxins play in disease severity, management and outcome in childhood is an emerging field requiring further exploration.

METHODS

A prospective multi-site study of Australian and New Zealand children hospitalized with S. aureus bacteremia (SAB), occurred over 24-months (2017-2018). Whole genome sequencing (WGS) data was paired with clinical information from the ISAIAH cohort.

RESULTS

353 SAB isolates were sequenced; 85% methicillin-susceptible S. aureus ([MSSA], 301/353); 15% methicillin-resistant S. aureus ([MRSA], 52/353). There were 92 sequence types (STs), most commonly; ST5 (18%) and ST30 (8%), grouped into 23 clonal complexes (CCs), most frequently CC5 (21%) and CC30 (12%). MSSA comprised the majority of healthcare-associated SAB (87%, 109/125), with principal clones CC15 (48%, 11/21) and CC8 (33%, 7/21). Panton Valentine Leukocidin (PVL)-positive SAB occurred in 22% (76/353); predominantly MSSA (59%, 45/76), community-onset (92%, 70/76) infections. For community-onset SAB, the only microbiological independent predictor of poor outcomes was PVL-positivity (aOR 2.6 [CI 1.0-6.2]).

CONCLUSION

From this WGS pediatric SAB data, we demonstrate the previously under-recognized role MSSA has in harboring genetic virulence and causing healthcare-associated infections. PVL-positivity was the only molecular independent predictor of poor outcomes in children. These findings underscore the need for further research to define the potential implications PVL-producing strains may have on approaches to S. aureus clinical management.

Management and Prevention of Staphylococcus aureus Infections in Children

Staphylococcus aureus is a common skin commensal with the potential to cause severe infections resulting in significant morbidity and mortality. Up to 30% of individuals are colonized with S aureus, though infection typically does not occur without skin barrier disruption. Infection management includes promptly addressing the source of infection, including sites of metastatic infection, and initiation of effective antibiotics, which should be selected based on local antibiotic susceptibility patterns. Given that S aureus colonization is a risk factor for infection, preventive strategies are aimed at optimizing hygiene measures and decolonization regimens for outpatients and critically ill children with prolonged hospitalizations.

Acute Multifocal Nonhematogenous Methicillin-Sensitive Staphylococcus aureus Osteomyelitis in a Healthy Adolescent: An Atypical Presentation

Osteomyelitis represents inflammation and infection of bone tissue by a pathogen. Acute osteomyelitis is more likely to be unifocal compared to a chronic process which tends to be multifocal and recurrent. Early diagnosis, aggressive appropriate antibiotic therapy and a multidisciplinary approach are essential for a satisfactory prognosis and improved outcome. We report an atypical case of acute multifocal methicillin-sensitive Staphylococcus aureus (MSSA) osteomyelitis.

Italian consensus on the therapeutic management of uncomplicated acute hematogenous osteomyelitis in children

BACKGROUND

Acute hematogenous osteomyelitis (AHOM) is an insidious infection of the bone that more frequently affects young males. The etiology, mainly bacterial, is often related to the patient's age, but it is frequently missed, owing to the low sensitivity of microbiological cultures. Thus, the evaluation of inflammatory biomarkers and imaging usually guide the diagnosis and follow-up of the infection. The antibiotic treatment of uncomplicated AHOM, on the other hand, heavily relies upon the clinician experience, given the current lack of national guidelines for the management of this infection.

METHODS

A systematic review of the studies on the empirical treatment of uncomplicated AHOM in children published in English or Italian between January 1, 2009, and March 31, 2020, indexed on Pubmed or Embase search engines, was carried out. All guidelines and studies reporting on non-bacterial or complicated or post-traumatic osteomyelitis affecting newborns or children older than 18 years or with comorbidities were excluded from the review. All other works were included in this study.

RESULTS

Out of 4576 articles, 53 were included in the study. Data on different topics was gathered and outlined: bone penetration of antibiotics; choice of intravenous antibiotic therapy according to the isolated or suspected pathogen; choice of oral antibiotic therapy; length of treatment and switch to oral therapy; surgical treatment.

CONCLUSIONS

The therapeutic management of osteomyelitis is still object of controversy. This study reports the first Italian consensus on the management of uncomplicated AHOM in children of pediatric osteomyelitis, based on expert opinions and a vast literature review.

Carbapenem-Resistant Klebsiella pneumoniae Osteomyelitis Treated with Ceftazidime-Avibactam in an Infant: A Case Report

Increasing cases of carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections have been observed globally where multi-drug resistance to CR-KP can make the infection difficult to treat. In recent years, the β-lactam/β-lactamase inhibitor, ceftazidime-avibactam (CAZ-AVI), has been developed to treat complicated urinary tract infections and complicated intra-abdominal infections. CAZ-AVI is approved for children over 3-month old but has yet to be investigated for cases of osteomyelitis. Only three case reports exist in literature on the use of CAZ-AVI for CR-KP osteomyelitis in adults. In this report, we present an infant with primary hematogenous osteomyelitis and septic arthritis in the right shoulder following surgical treatment for a heart murmur. Bacterial isolation revealed a strain of CR-KP, which was successfully treated with CAZ-AVI after initial administration of imipenem-based treatments.

Culture-negative chronic hematogenous osteomyelitis in a two months old girl: a case report

Background

Previous articles have focused on the diagnosis and treatment of acute hematogenous osteomyelitis. Here, we present a case of chronic hematogenous osteomyelitis in a 2-month-old girl. The diagnostic procedure was unusual and difficult due to negative culture results.

Case presentation

A girl aged 2 months and 23 days had fever and swelling in her right lower leg for 7 days. On the basis of her medical history, physical, and histological examination results; and radiologic and magnetic resonance imaging findings, a diagnosis of chronic osteomyelitis was made. The patient underwent surgical treatment and was discharged successfully. The patient showed good recovery and no sequelae at the 12-month follow-up.

Conclusion

Hematogenous osteomyelitis in babyhood is different from that at any other age. Hematogenous osteomyelitis-related bone destruction in babyhood is more serious and occurs faster. The transition from acute hematogenous osteomyelitis to chronic hematogenous osteomyelitis takes only 7 days. To the best of our knowledge, this chronic hematogenous osteomyelitis patient is the youngest ever reported.

Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

3D Cocultures of Osteoblasts and Staphylococcus aureus on Biomimetic Bone Scaffolds as a Tool to Investigate the Host-Pathogen Interface in Osteomyelitis

Osteomyelitis (OM) is an infectious disease of the bone primarily caused by the opportunistic pathogen Staphylococcus aureus (SA). This Gram-positive bacterium has evolved a number of strategies to evade the immune response and subvert bone homeostasis, yet the underlying mechanisms remain poorly understood. OM has been modeled in vitro to challenge pathogenetic hypotheses in controlled conditions, thus providing guidance and support to animal experimentation. In this regard, traditional 2D models of OM inherently lack the spatial complexity of bone architecture. Three-dimensional models of the disease overcome this limitation; however, they poorly reproduce composition and texture of the natural bone. Here, we developed a new 3D model of OM based on cocultures of SA and murine osteoblastic MC3T3-E1 cells on magnesium-doped hydroxyapatite/collagen I (MgHA/Col) scaffolds that closely recapitulate the bone extracellular matrix. In this model, matrix-dependent effects were observed in proliferation, gene transcription, protein expression, and cell–matrix interactions both of the osteoblastic cell line and of bacterium. Additionally, these had distinct metabolic and gene expression profiles, compared to conventional 2D settings, when grown on MgHA/Col scaffolds in separate monocultures. Our study points to MgHA/Col scaffolds as biocompatible and bioactive matrices and provides a novel and close-to-physiology tool to address the pathogenetic mechanisms of OM at the host–pathogen interface.